Stateful processing for stateless forwarding element

Some embodiments provide a method for performing stateful processing of a packet at a flow-based managed forwarding element (MFE). The method receives a packet at the MFE without stateful connection status information. The method sends the packet to a module separate from the MFE that stores stateful connection information for a plurality of connections. The method receives the packet from the module with stateful connection status information appended to the packet. The method performs an action on the packet based on the appended stateful connection status information.